Edited 21 Mar 2019 00:05, last year, edited by M636C

Boeing has made a basic error in the 737 Max 8 aircraft, they have fitted heavier engines further back on the wings causing the aircraft to be tail heavy and instead of making a new wing and or engine mounts they have tried to cure the error in software
All the information I've found suggests that the engines were actually moved forward and upward to accommodate their larger diameter. I have heard the statement about the engines being moved back but I've found nothing to support it. Something else might have altered the balance. The wing was altered between the 400 and 800 series but only the winglets were changed for the -8.

From Wikipedia

In mid-2011, the objective was to match the A320neo's 15% fuel burn advantage, but the initial reduction was 10–12%; it was later enhanced to 14.5%: the fan was widened from 61 inches to 69.4 inches by raising the nose gear and placing the engine higher and forward, the split winglet added 1–1.5%, a relofted tail cone 1% more and electronically controlling the bleed air system improves efficiency.

So it isn't  immediately clear why the extra concern about stalling required the new software....

Peter